Selective-type change-speed transmission



SBLECTIVE TYPE CHANGE S'EED TRANSMISSION Filed Aug. 17, 1921 2 Shee'IS-Sheet 2 ALEXANDER oierswoin espinasse ined mgmt iv. wel.' sei-nu 493,035.3.

To ali @nimm mog; concern:

3e ii known that l, .einstimmen Giuswomi Hnnrmsnorry e citizen of the United States, residing in he eit37 of Bristoi, in the Starte oi Rhode island, have invented certain ond useful improvements in Selective- '..ype Change-Speed Transmission, of which ine following is o. specification, reference being had to lie acconnjjmnying drawings, forming e pero heren-i.

'.liis invention relates io an improved change 'speed ronsniission of the selective type and is designed primarily with referonce io its; adaptation to five speeds forward and reverse. A. transmission of this che-racier to be practical and useful from lioltli .the engineering and the commercial scandi [mini niust satisfy requirements which have not* yet been met in five speed transmissions'. ri'lie` psincipni. object of the present inien tion lis to pviovide o construe-tion which, ywhen adapted to. a five speed ransmission, iviiiinnlro ille box as available for ordinary automotive uses as rire accepted type of three und iou speed boxes now in vogue; lmi is to say, .the improved transmission guey ire liousedinslsiiortcompeoi bon'. which not onlyjperniits it to lie mounted on e chassis insa-cordones with accepied practise bue also insures short stii shas'nith resulfuig quiet operation. The change speed gears ilieniseives are all of relatively smell. rlionieier and vvery one froml another by slight degrees of graduation, ali or' the tooili' speeds being'iow und the sresses about the seine ilirougliou'a'; iThis design, us will be appreciated, inslres i'or coropactness end longer iifo. :in reoiizing this advantage i compound reduction in two ppor'ed on the counter shaft;

"here lies been provided in the improved Lsucii as first and second),

A compound sleeve. having' consen. rnesli gee-rs seins? loosely io erkent tins compound reduction when 'the jopriele gears on the spline slia's inesiiec iiierwilzli uri Uf ferriere oi' the iimgjJ-rored irons Isides of lie v in :die simpiici-y sind speed rsnsniission u Single shifter empl und ilus in iis vii-rione posi iions 'i ares forks of purpose of meshing speeds in ther, in securing esclxciiange of speed ony known type `for lloe 'forward speed changing n" oi'iersing mechanism. In 'the five lie gears for f' appropriate combinations. Fnru single needs to be moved, the spline shaft- .lniving slidsbljyv mounted thereon only ilu-ee cliunge speed lgears, any one of which inoyflie picked up by the sliifterllever through proper manipulation when a speed change io lie accomplished. Noi. oniy is the improved runsrnission characterized by simpl-iri* end iewness of parts Iin this one respece 'om ii; is to be noted tha a inininiuln number nfgenrs is lio be found within die box for Hue securing' of such u 'le number of speed ratios.

These and other objects and advantages of lie improved transmission will appear to one skilled in lie "en: et greater lengli in conneoion .Wiii the desiled description of the illustrated embodiment shown in the ccornps nyingr drawings, wherein Finire l is s View in veriiicsl section through 'die improved ltrfinsn'iission as, housed in e snileiie I Figure is n View .in transverse s through ille set slionf'n in Figure l end teken on he pianos indicoed by ille broken lines of gnre i and loon-ing in the direction o1 lle arrows.

Figure 3 is n scheinaiic' view showing all of lie goers of the transmission developed in n plone in order that their intelP-` reluion for didere/ni', speed rufiios may be more readily nndersiood.

The enulnidiinen oi' the improved transmission illustrated herein is for e five speed und reverse boxior use in o motor vehicle, and porieuiariy s, truck, bei, is to be nndersiood diet eert-ain features of i'lie invention inu'jf be equally advantageous in eirensinission nuvingr 's cliieren nurnlier of speed rsios end designed for Work oi some olier clisrwer.

in tile dressings prime mover shaft ci is indiesied journeled in rliebearings 5 eclion M 'l L" in die ein. i-:od oi nl 1 er c, this siiei't Cerwin?" at rs ner end n. oonsienily roi. n arisingspor and jaw clutch of, in s web o" oi ille cese.

inlooerd i being1 provid o, the rear a. A spline shari; e is jonrneied ro'beizebly 4Wil'hin Ane in Connie! oiion wml lie drive siiofi ne spline sliee' interino inber for which i oil-the d". e simil; e may Toe die end weil of rifleci @-3 'une inner eno, oi

@n elle -soiine' ner by a single shifter lever, indicated at Zr. The invention is not concerned with the details of construction of the shifting. Ineclr auisui, except in so far as the construction and arrangement of the gears permit their operation by a single lever.`

In the box c is also journaled what will be hereinafter termed the first counter shaft Z, bearings Z, Z2 being 'provided therefor vthe bearing Z are keyed, or otherwise secured to the shaft Z, spuugears G H with which may be mashed selectively the sliding gears g, Zz., respectively. Intermediate the ends of the first'counter shaft Z is revolubly mounted a sleeve a on which are cut or otherwise provided compound gears n?, yn.2 which may be engaged b v the sliding gears t, i, respectively. 0n the remote end of the shaft Z is cut or otherwise provided a pinion Z with which meshes constantly a gear L keyed or otherwise secured to a second counter shaft L journaled rotatably in the casing c. The second counter shaft L has thereon a second gear L2 which is in.

constant mesh with'one of the compound gears n2 on the sleeve a. The sliding gear may be meshed with the gear L on the shaft L in order to effect.- reverse speed.

Thus far, the elements have been described in their physical relation to onel another with special reference to the gear-casing c and the lfunction of each has been indicated briefly. F or an understanding of the co ordinated functioning of the parts, however, reference isto be had to Figure 3. Fifth speed is direct and is gotten by sliding the gear g towards the jaw clutch a2 untilthe cooperating clutch teeth q2 on the face of the lest gear g engage therewith. At this time the spline shaft e rotates with the drive shaft a. A comparatively slight reduction is provided between fifth speed and fourth speed in order that shifting into fourth will be easy, a condition not heretofore general-ly realized.' When` the jaw clutch z2 is disengaged from the clutch 0,2, the gear g is -free to be slid /into mesh with the gear G fixed on the first counter shaft Z. Since the.

gears a and'm are in constant mesh the first counter shaft Z will constantly revolve. The fourth speed is obtained through meshing of the gears g, G. For third speed the gear l1. is slid into mesh with the gear H. For second speed the gearh is slid in the opposite direction into mesh with the compound pinion 1t on the freely revolving sleeve 1t. The power is applied to the gear 91. for rotation of the gear Z1. and the spline shaft c by passing through the constant mesh gears Z, L, L2, n?. First speed is obtained by sliding the gear i into mesh with the compound pinion al. Power is delivered in the manner just indicated. Reverse speed, as indicated hereinbefore, is obtained by sliding the gear a' into' mesh with the gear L.

From the description given it will be ap-.

preciated that the transmission set provided is, to all intents and, purposes, as simple and compact in construction and operation as the accepted types of three and four speed transmission, the necessary elements for the additional speed ratio heilig included without adding to the bulk of the set or necessitating employment of special selector de vices therefor. Only twelve gears are used for obtaining six speeds, that is, five speeds forward and one reverse. Single sliding 'ge-ars, only three in number, are needed in order to obtain these six speeds. The difii culties attending the manufacture of double slidingr gears and the complication of their operation are avoided. All fof the gears within reasonable limits are uniformly graduated in size, that is to say; there are no such great differences in pitch diameters as result in unduly high tooth speeds or tooth stresses nor are the shafts and gears subjected in any instant to deterioratingtwist ing and tol'sionalstresses. The useot1 compound gears for two of the speeds vmakes it possible to secure this uniform graduation in pitch diameters with the resulting compactness and longer life. The box itself for the transmission is short and the shafts therein are correspondingly stiff 'and insure quiet operation. Manufacturing and engineering requirements are entirely satisfied in .the simplicity and accessibility of all of the elements.

As indicated hereinbefore some of' the devices of the improved transmission may be adapted to boxes for other conditions of use without departing from the spirit of the' invention.

I claim as my invention:

1.. Change speed transmission ot' the selective type including a spline shaft, change speed gears -slidable thereon selectively, a first counter shaft having gears rotatable therewith to be engaged by certain of said first named gears selectively, a compound gear rotatable freely onsaid counter shaft and adapted to be engaged selectively by certain of said first named gears and means'V to drive said compound'gear.

2. Change speed transmission of the selective type including a spline shaft, single change speed gears slidable selectively thereon, a first `counter shaft having gears thereon to'be engaged selectively by certain of said first named gears, a compound newness gear revolnhle freely on said counter shalt and adapted to be engaged selectively loy certain of said irst named 1gears and a second counter shaft vdriven from seid first nenied counter shaft 'oy constant mesh gears and having thereon a gear in constant niesli with one of said compound gears.

43. Change speed' transmission for rive speeds forward and reverse including a spline shaft having three single Slidable gears thereon, ai drive shaft having a gear thereon, a first counter shaft having a gear in.constent mesh with the gear on said drive shaft, two gears carried with the said counter shaft for engagement selectively by certain oit' said gears on said spline shaft,

a compound gear revoluhle freely on said counter shaft and engageahle selectively 'oy certain or said sliding; gears, a pinion can ried with said counter shaft, sind a second counter shaft having two gears thereon, one oi said gears being in constant mesh with said pinion andthe other of said gears being in constant nicsh with one of said compound gears. i

el. in a change speed transmission, a

counter shalt. a compound gear Irevoinloie 'reeiy thereon, a pinion on the counter shaft, and e second counter shaft carrying a gear in cfnstant mesh with seid pinion and e gear in constant mesh Wit-h one oi" said .compound gears.

D .Five speeds forward and reverse, the coinliination driving and driven shafts including spline shaft, gears of different ratio ln s. change speed transn'iission 'for to transmit the driving torque` to the driven shaft, respectively, a counter shaft on which seid gears are carried, three single gears slidable-on the' spline shaft selectively to coact with the rstmamed gears, respectively, to eii'ectfallve oi' said speed changes, forks for the respective slidinw gears, and a single shifter lever engaging said forks seieetively.

6. Change speed transmission inciuding a driven shaft and a counter shaft, sliding gears on one of said shafts, fixed 'gears on the other of said shafts for selective engagement by 'the sliding gears, a second counter shaft driven from the shaft having the gears iixed thereon and additional gears to effect a" compound reduction in tivo of the speed changes and interposed operatively between the shaft having the gears fixed thereon and the sliding gears.

7. Change speed transmission, including .a drive short, a driven shaft in line therewith, e. counter shaft, engageable gears on the respective shafts, including a compound gear mounted loosely on one of seid shafts, certain of said gears heine` siidnlele selectively whereby five forward speed changes an reverse may be eilected 'oetiveen the drive shaft and the driven shaft, end a cox in which said shafts are journaled, the driven shaft beingr journaled it its inner end in the drive shaft.

This specification signed this 15th day of August, i921.

ALEXNBER GRISWOLD HERRESHOFF. 

